Liquid accumulators have already been implemented comprising a vessel communicating with a hydraulic installation that may be under high pressure, the fluid contained in the vessel being partially liquid and partially gas. The liquid accumulator may co-operate with a system for controlling or regulating the level of liquid in the vessel. However, such a system for controlling or regulating the level of liquid requires level sensors to be used together with regulation circuits which are usually of the electronic type. This constitutes a major drawback for applications to systems conveying fluids which are toxic or corrosive, such as the fluids used in the nuclear and chemical industries, or in applications using fluids that are volatile, e.g. in a cryogenic stage of a satellite launcher.
The present invention seeks to remedy the drawbacks of the prior art and make it possible to provide an accumulator for liquid under high pressure and at regulated level without requiring the use of electrical type regulation circuits or sensors and which makes it possible to use purely mechanical means in simple and robust form for obtaining accurate, sensitive and stable regulation of the level of a liquid, over a wide range of pressures and without any risk of damaging the regulation system.